scholarly journals Neuroprotective Mechanisms of Calycosin Against Focal Cerebral Ischemia and Reperfusion Injury in Rats

2018 ◽  
Vol 45 (2) ◽  
pp. 537-546 ◽  
Author(s):  
Yong Wang ◽  
Qianyao Ren ◽  
Xing Zhang ◽  
Huiling Lu ◽  
Jian Chen

Background/Aims: Emerging evidence suggests that autophagy plays important roles in the pathophysiological processes of cerebral ischemia and reperfusion injury. Calycosin, an isoflavone phytoestrogen, possesses neuroprotective effects in cerebral ischemia and reperfusion in rats. Here, we investigated the neuroprotective effects of calycosin against ischemia and reperfusion injury, as well as related probable mechanisms behind autophagy pathways. Methods: A cerebral ischemic and reperfusion injury model was established by middle cerebral artery occlusion in male Sprague-Dawley rats. Neurological scores, infarct volumes, and brain water content were assessed after 24 h reperfusion following 2 h ischemia. Additionally, the expression of the autophagy-related protein p62 and NBR1 (neighbor of BRCA1 gene 1), as well as Bcl-2, and TNF-α in rat brain tissues was measured by RT-PCR, western blotting and immunohistochemical analyses. Results: The results showed that calycosin pretreatment for 14 days markedly decreased infarct volume and brain edema, and ameliorated neurological scores in rats with focal cerebral ischemia and reperfusion. It was observed that levels of p62, NBR1 and Bcl-2 were greatly decreased, and levels of TNF-α significantly increased after ischemia and reperfusion injury. However, calycosin administration dramatically upregulated the expression of p62, NBR1 and Bcl-2, and downregulated the level of TNF-α. Conclusions: All data reveal that calycosin exerts a neuroprotective effect on cerebral ischemia and reperfusion injury, and the mechanisms maybe associated with its anti-autophagic, anti-apoptotic and anti-inflammatory action.

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Yong-Hua Tuo ◽  
Zhong Liu ◽  
Lei Feng ◽  
Zhong-Song Shi

Background: MicroRNA-29a (miR-29a) is involved in regulating cerebral ischemia process, but its underlying mechanism is unclear. We previously showed that inhibition of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX4) pathway improves the neurological outcome and increases the expression of miR-29a in transient middle cerebral artery occlusion (tMCAO) animal model. This study investigated the role of miR-29a in cerebral ischemia and reperfusion injury after mechanical reperfusion. Methods: The intraluminal filament tMCAO model was established in male rats with 2 hour ischemia followed by reperfusion. The expression of miR-29a and NOX4 in the infarction core and peri-infarct cortex were quantified at 0, 3, 12, and 24 hour after reperfusion. Permanent MCAO model was also evaluated after 2 hour and 24 hour ischemia. Intravenous miR-29a agomir was delivered immediately after reperfusion. Infarct volume, brain water content, neurological score, blood-brain barrier damage, and levels of miR-29a and NOX4 were determined at 24-hour after cerebral ischemia. Results: MiR-29a levels in the infarction core and peri-infarct cortex were significantly decreased at 3 hours after reperfusion in tMCAO group compared with the sham-operated group. The decreased levels of miR-29a lasted for 24 hours after cerebral ischemia. Dual-luciferase reporter system showed that NOX4 was the direct target gene of miR-29a. Intravenous miR-29a agomir increased the expression of miR-29a and suppressed NOX4 up-regulation in both the infarction core and peri-infarct cortex at 24-hour after ischemia compared with the tMCAO group (all p<0.05). Intravenous miR-29a agomir reduced infarct volume (24.7% ± 4.0% versus 37.8% ± 7.5%, p<0.01) at 24-hour after ischemia compared to the tMCAO group. MiR-29a agomir attenuated brain edema and reduced reperfusion-induced blood-brain barrier breakdown, resulting in improved neurological outcome (all p<0.05). Conclusions: MiR-29a overexpression protects against cerebral ischemia and reperfusion injury via downregulating NOX4. Infusion of miR-29a agomir immediately after reperfusion represents a novel adjunctive therapeutic strategy to improve outcome after mechanical reperfusion for acute ischemic stroke.


Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 270 ◽  
Author(s):  
Weijie Xie ◽  
Ping Zhou ◽  
Yifan Sun ◽  
Xiangbao Meng ◽  
Ziru Dai ◽  
...  

Cerebral ischemia-reperfusion is a complicated pathological process. The injury and cascade reactions caused by cerebral ischemia and reperfusion are characterized by high mortality, high recurrence, and high disability. However, only a limited number of antithrombotic drugs, such as recombinant tissue plasminogen activator (r-TPA), aspirin, and heparin, are currently available for ischemic stroke, and its safety concerns is inevitable which associated with reperfusion injury and hemorrhage. Therefore, it is necessary to further explore and examine some potential neuroprotective agents with treatment for cerebral ischemia and reperfusion injury to reduce safety concerns caused by antithrombotic drugs in ischemic stroke. Ginseng Rg1 (G-Rg1) is a saponin composed of natural active ingredients and derived from the roots or stems of Panax notoginseng and ginseng in traditional Chinese medicine. Its pharmacological effects exert remarkable neurotrophic and neuroprotective effects in the central nervous system. To explore and summarize the protective effects and mechanisms of ginsenoside Rg1 against cerebral ischemia and reperfusion injury, we conducted this review, in which we searched the PubMed database to obtain and organize studies concerning the pharmacological effects and mechanisms of ginsenoside Rg1 against cerebral ischemia and reperfusion injury. This study provides a valuable reference and clues for the development of new agents to combat ischemic stroke. Our summarized review and analysis show that the pharmacological effects of and mechanisms underlying ginsenoside Rg1 activity against cerebral ischemia and reperfusion injury mainly involve 4 sets of mechanisms: anti-oxidant activity and associated apoptosis via the Akt, Nrf2/HO-1, PPARγ/HO-1, extracellular regulated protein kinases (ERK), p38, and c-Jun N-terminal kinase (JNK) pathways (or mitochondrial apoptosis pathway) and the caspase-3/ROCK1/MLC pathway; anti-inflammatory and immune stimulatory-related activities that involve apoptosis or necrosis via MAPK pathways (the JNK1/2 + ERK1/2 and PPARγ/HO-1 pathways), endoplasmic reticulum stress (ERS), high mobility group protein1 (HMGB1)-induced TLR2/4/9 and receptor for advanced glycation end products (RAGE) pathways, and the activation of NF-κB; neurological cell cycle, proliferation, differentiation, and regeneration via the MAPK pathways (JNK1/2 + ERK1/2, PI3K-Akt/mTOR, PKB/Akt and HIF-1α/VEGF pathways); and energy metabolism and the regulation of cellular ATP levels, the blood-brain barrier and other effects via N-methyl-D-aspartic acid (NMDA) receptors, ERS, and AMP/AMPK-GLUT pathways. Collectively, these mechanisms result in significant neuroprotective effects against cerebral ischemic injury. These findings will be valuable in that they should further promote the development of candidate drugs and provide more information to support the application of previous findings in stroke clinical trials.


Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 512 ◽  
Author(s):  
Xie ◽  
Zhu ◽  
Dong ◽  
Nan ◽  
Meng ◽  
...  

Ischemic stroke is a clinically common cerebrovascular disease whose main risks include necrosis, apoptosis and cerebral infarction, all caused by cerebral ischemia and reperfusion (I/R) injury. This process has particular significance for the treatment of stroke patients. Notoginseng leaf triterpenes (PNGL), as a valuable medicine, have been discovered to have neuroprotective effects. However, it was not confirmed that whether PNGL may possess neuroprotective effects against cerebral I/R injury. To explore the neuroprotective effects of PNGL and their underlying mechanisms, a middle cerebral artery occlusion/reperfusion (MCAO/R) model was established. In vivo results suggested that in MCAO/R model rats, PNGL pretreatment (73.0, 146, 292 mg/kg) remarkably decreased infarct volume, reduced brain water content, and improved neurological functions; moreover, PNGL (73.0, 146, 292 mg/kg) significantly alleviated blood-brain barrier (BBB) disruption and inhibited neuronal apoptosis and neuronal loss caused by cerebral I/R injury, while PNGL with a different concertation (146, 292 mg/kg) significantly reduced the concentrations of IL-6, TNF-α, IL-1 β, and HMGB1 in serums in a dose-dependent way, which indicated that inflammation inhibition could be involved in the neuroprotective effects of PNGL. The immunofluorescence and western blot analysis showed PNGL decreased HMGB1 expression, suppressed the HMGB1-triggered inflammation, and inhibited microglia activation (IBA1) in hippocampus and cortex, thus dose-dependently downregulating inflammatory cytokines including VCAM-1, MMP-9, MMP-2, and ICAM-1 concentrations in ischemic brains. Interestingly, PNGL administration (146 mg/kg) significantly downregulated the levels of p-P44/42, p-JNK1/2 and p-P38 MAPK, and also inhibited expressions of the total NF-κB and phosphorylated NF-κB in ischemic brains, which was the downstream pathway triggered by HMGB1. All of these results indicated that the protective effects of PNGL against cerebral I/R injury could be associated with inhibiting HMGB1-triggered inflammation, suppressing the activation of MAPKs and NF-κB, and thus improved cerebral I/R-induced neuropathological changes. This study may offer insight into discovering new active compounds for the treatment of ischemic stroke.


2013 ◽  
Vol 33 (4) ◽  
pp. 583-592 ◽  
Author(s):  
Xiang Yun ◽  
Victor D Maximov ◽  
Jin Yu ◽  
g Zhu ◽  
Alexey A Vertegel ◽  
...  

Stroke is one of the major causes of death and disability in the United States. After cerebral ischemia and reperfusion injury, the generation of reactive oxygen species (ROS) and reactive nitrogen species may contribute to the disease process through alterations in the structure of DNA, RNA, proteins, and lipids. We generated various nanoparticles (liposomes, polybutylcyanoacrylate (PBCA), or poly(lactide-co-glycolide) (PLGA)) that contained active superoxide dismutase (SOD) enzyme (4,000 to 20,000 U/kg) in the mouse model of cerebral ischemia and reperfusion injury to determine the impact of these molecules. In addition, the nanoparticles were untagged or tagged with nonselective antibodies or antibodies directed against the N-methyl-D-aspartate (NMDA) receptor 1. The nanoparticles containing SOD protected primary neurons in vitro from oxygen-glucose deprivation (OGD) and limited the extent of apoptosis. The nanoparticles showed protection against ischemia and reperfusion injury when applied after injury with a 50% to 60% reduction in infarct volume, reduced inflammatory markers, and improved behavior in vivo. The targeted nanoparticles not only showed enhanced protection but also showed localization to the CA regions of the hippocampus. Nanoparticles alone were not effective in reducing infarct volume. These studies show that targeted nanoparticles containing protective factors may be viable candidates for the treatment of stroke.


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